1. Field of the Invention
The present invention relates to slider needles for warp knitting machines comprising a slider which is guided between the side walls of a slot in the forward face of the needle shaft.
2. Discussion of the Relevant Art
In known slider needles of the foregoing type (DE-PS1760140) it is known to provide both the slider and the slot with parallel side walls. The slot breadth is slightly larger than the slider thickness so that the slider may rest entirely across its entire height, in the said slot. The edges of the slot meeting the forward surface of the needle shaft are rounded to avoid sharp edges. The closing portion of the slider is comparatively short and is attached to a slider shaft protruding from the slot.
During use these sliders are subjected to substantial sideward forces. These forces cause the slider to rest on one or the other side wall. The friction caused by the reciprocated motion gives rise to abrasion at the junction of the side wall of the slot and its forward face. This eventually gives rise to sharp, knife-like edges which interfere with the stitches lying on the needle shaft so that either stripes are formed in the fabrics or the filaments of the stitch thread are damaged or even cut. This particular problem is well known and discussed in DD-PS14665. The solution provided previously has been in either constructing the slider to be so big that it protrudes from the slot, which has the disadvantage of providing an excessive cross section for the needle; or the slot is formed by the rearward side of the needle and the slider led to the hook side through an opening therein, which leads to difficulties both in construction and in use.